Respect shared-library and projectComms feature flags

[Steve-Mcl]

part two of three

Description

• Project Nodes Feature
  • Adds boolean featureEnabled to projectLink object which is persisted in the settings file
  • sets projectLink.broker.url, projectLink.broker.username & projectLink.broker.password to '' if featureEnabled===false
• Shared Library Feature
  • Prevents library being loaded if its feature flag is false

Additional to this (happy to remove)

Added ability to run project-link nodes from source in developer environment by checking process.env.NODE_ENV === "development" and the nr-project-nodes src is in the expected relative location. This was necessary for testing the changes required for https://github.com/FlowFuse/flowfuse/issues/3560 Would like to keep it but can remove if requested.

Related Issue(s)

https://github.com/FlowFuse/flowfuse/issues/3560

Checklist

• [x] I have read the contribution guidelines
• [x] Suitable unit/system level tests have been added and they pass
• [ ] Documentation has been updated
  • [ ] Upgrade instructions
  • [ ] Configuration details
  • [ ] Concepts
• [ ] Changes flowforge.yml?
  • [ ] Issue/PR raised on FlowFuse/helm to update ConfigMap Template
  • [ ] Issue/PR raised on FlowFuse/CloudProject to update values for Staging/Production

Labels

• [ ] Backport needed? -> add the backport label
• [ ] Includes a DB migration? -> add the area:migration label